Fiber-optic gyroscopes (FOGs) belong to a class of rotation sensors that employ an optical interferometer to measure rotation rate by means of the Sagnac eŸect. ™e ring laser gyro also belongs to the family of rate sensors that employ the Sagnac eŸect to measure rotation. ™e interferometric ˜ber-optic gyroscope (IFOG) is a ring interferometer that uses a multiturn optical ˜ber coil to enhance the Sagnac eŸect induced by rotation with respect to inertial space. A signi˜cant advantage of the FOG is that it has no moving parts and hence the resulting solid state architecture ensures high reliability. Other bene˜ts include scalability, high precision and accuracy, and low power consumption.